1. Field of the Invention
The present invention relates to an error compensation device for a disk signal reproduction apparatus that reads out digital data from a digital disk on which the digital data is recorded along a spiral track, such as a CD, and reproduces a signal.
2. Description of the Related Art
Conventionally, in a digital audio disk, when there is a region from which signal pits of the disk cannot be read by an optical pickup because of a damage of the disk, contamination, or the like, a problem is produced that reproduction of an audio signal is stopped there, or, even when reproduction of the audio signal is continued, the reproduced sound is once interrupted and a time lag is produced in the reproduced music.
Japanese Patent Unexamined Publication No. Hei. 6-12773 discloses the following technique. When audio data is read out from data on a disk and an audio signal is reproduced at a high speed, a memory for CD-ROM data is used as an input buffer memory of an audio signal processing unit. While EFM demodulated data is sequentially written into the memory, the written data is sequentially read out at the single speed. When the writing of data into the audio signal processing unit almost exceeds the read address, the data writing is stopped, only the reading is conducted, and an optical pickup is jumped back by a predetermined number of tracks. At the timing when a vacant area is produced in the memory, the data after the stop of the writing is again written into the memory.
Japanese Patent Unexamined Publication No. Hei. 6-168541 discloses the following technique. "A quintuple speed mode or a double speed mode is set as a special reproduction mode. In the case where an instruction for automatic level response is given, the sound state is checked. If the current state is a silent state, the system waits for generation of sound for a constant time period. If sound is generated, data of the sound signal is written into a memory. The sound signal data is read out from the memory, namely, the timing of starting the reproduction of the sound signal is changed, so that the rising of the sound is reproduced. In the case where an instruction for forced level response is given, the timing of starting the reproduction is changed irrespective of the sound state, so that the rising of the sound is reproduced."
In both of the conventional techniques, when there is a region from which signal pits of a disk cannot be read by an optical pickup because of a damage of the disk, contamination, or the like, there arises a problem that reproduction of an audio signal is stopped, or, even when reproduction of the audio signal is continued, the reproduced sound is once interrupted and a time lag is produced in the reproduced music.